I used to think that I had depression when I would really get stuck in my head. Later I found that it was just isolation and what I really needed was interacting with people on the same wavelength of vibrations. That changed my whole perspective.
The right people make all of the difference.
Wow that is quite something!! Such a seemingly simple and obvious "answer" yet I wonder how many other people don't realise it. Getting stuck in your own head can be incredibly toxic... especially when you are alone.